The Somali government and African Union forces have retaken the southern port town of Merka, having pulled out on Friday, allowing Al Shabab fighters to seize the city.
Residents say that some fighting took place as AMISOM forces pushed out the militants. Civilian casualties have also been reported due to latest fighting.
Marka lies a around 100 kilometres from Mogadishu, and had been under Amisom control since 2012.
The withdrawal by the AU forces still remains a mystery, though Amisom has called it a tactical withdrawal.
In recent months, Amisom has pulled back from the conflict areas. Kenyan forces have withdrawn from four towns and Ugandan troops from another six.
The Somali government is desperate for Amisom to get back on the offensive to boost security ahead of elections scheduled in little more than six months from now, but the AU has said Amisom lacks the resources to move forward.